In general, a quantum well is a type of heterostructure formed by joining together layers of different semiconductor materials having different bandgaps. For example, a quantum well may be formed by sandwiching a gallium arsenide layer between two aluminum arsenide layers, the gallium arsenide layer being the well layer. The interface that occurs between the different layers may be referred to as a junction. In quantum well junctions, charge carriers are confined in the well and energy levels are quantized.
Quantum well structures have a variety of practical applications. For example, quantum well structures may be used to improve performance in various electronic devices, optical devices, or optoelectronic devices, including but not limited to laser diodes, photodetectors, and ballistic transport transistors.
Various known techniques exist to grow or manufacture quantum well structures. Precise control of layer thickness and defect-free interfaces may be important to tune the characteristics of the structure.